Collapsible antennas raised and lowered by electric motors are widely used on automobiles. Such antennas are typically mounted in a fender well. The power and strength required for the drive mechanism has, in the past, required a relatively bulky and heavy antenna and motor assembly, requiring substantial space and a relatively strong mounting bracket within the fender well. With the present popularity of smaller and lighter automobiles, the available space for automotive accessories is at a premium. The space used by one accessory takes from that available for another. In addition, the weight of an automobile has a substantial effect upon its gasoline mileage and substantial effort is being made to reduce the total weight of automobiles. Accordingly, the need for compact and lightweight accessories, including motor-operated antennas, is especially great. Nevertheless, a motor-operated antenna must be rugged and powerful enough to function under the adverse conditions of vibration, snow, ice, and the like, and be low in cost and reliable in its operation.